Slack - A messaging app for teams who see through the Earth!
Better Notes - Simple notes app that ties notes together with #hashtags
Mattermost - Mattermost is an open source alternative to Slack.
flomo - The minimal memo-taking tool to empower better thinking
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Paper - Super-clean writing space with a lot of configurability that stays out of sight when you don’t need it.